Heavy Tanks in the Imperial Japanese Army

Writing long posts like this are hard for me, please dont mind grammar errors.​

During the Great War Era, the most advanced tank of the era could be given to the Renault FT, a French made tank that entered service in 1917 and was utilized until 1949. During the late 20's, the Japanese purchased 10 Renault variants for Imperial Service. These Renaults were called the [Otsu] Gata Senshas ([Tank] B Models), Japan's first lend lease tanks. They were used and examined, however none of them saw any war experience. The farthest they were placed was during the Shanghai incident, where Japanese forces defended themselves against attacking Chinese Nationalists. There they were used and the results were lack-luster, as expected for a tank in which its prime days were ended. Many were captured by the Chinese and sued in their endeavors.

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Imperial Japanese Renaults mobilized outside Shanghai, 1932​

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Along with the arrival of the French RT tanks, the Imperial Japanese purchased numerous tanks from Great Britain. These tanks included things such as the Mark IV Female, Whippet, Vickers C, etc. These tanks were utilized and examined for testing so the Imperial Japanese could too develop their own tanks. This took bloom in 1928, when Japan built its first tank, the Experimental I Chi-I. Japan referred to it as a Heavy tank, however under modern standards it could have been seen as a medium by far. This tank was the pinnacle for future Japanese tank designs, which came shortly after.

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Shortly after the production of the Experimental tank, the Japan began working on light, medium, armoured cars, and yes.. heavy tanks. During this time frame Japan successfully built 2 heavy tanks. The Type91 finished its production in 1931. With 5 crew members and mounting a Type94 7cm Tank Gun. Only one tank of the series was built, and was canceled in favor of a more favorable model. However this did not stop the design from continuing. In 1935 , the Osaka manufacturing company produced the Type95, a modernized version of the Type91. The tank was given more armour, an improved suspension, and two frontal chassis turret mounting a 3,7cm. 4 tanks were built, however it too was stopped and the Type HT series was permanently halted.

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Japanese Type91 (Left) and the Type95 (Right)​

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In 1940 the Imperial Japanese Army began the heavy tank projects again. This time however, the Japanese required something heavy and powerful to be used in Manchukuo against the Soviet Union. This heavy tank project was designed by Hideo Iwakuro, a major general in the Imperial Japanese Army. The plan entitled a superheavy 100 ton model that was to exceed the limits of tank concepts at the time. The Imperial Japanese Army gave the tank the title "Iwakuro 100t", no Type disambiguation was given at the time. The Iwakuro 100t mounted a single experimental 10,5cm cannon (150mm of penetration @ 100 meters), along with a 7,5cm gun on the hull turret. The tank was produced with a single prototype... however the tank experienced heavy mechanical issues and was discontinued shortly after trials began.

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Only one tank model was built, however it was given additional armoured played that were bolted on to provide extra armouring. I will list the armour levels below for you here. ​

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Hull/Turret Front: 75mm + 75mm plate (Total of 150mm)​

Hull/Turret Side: 35mm + 35mm plate (Total of 70mm)

Hull/Turret Rear: 35mm + 35mm plate (Total of 70mm)

The Iwakuro was not the extent of Japanese Heavy tanks however, it went on to even larger extreme proportions. The following series of tanks, came a year later... and were to be known as the O-I series. The O-I (Meaning Big 1, or Heavy 1) were never given a Type disambiguation for their models. This was only for mass production tanks and projects. They were referred to by their weight displacement. The next tank after the Ikwauro 100t to follow was the O-I 100t. It followed the design of the Iwauro, but was modified to larger standards than the previous counterpart. Containing a primary turret mounting a 10,5cm Cannon (Same as Iwakuro, better penetration via range), but with two multi purpose chassis turrets a single 5,7cm cannon per. It was built with one prototype, but was sunk in the ground while on testing trials.This happened due to the extreme weather in th region the trials were conducted in. In comparison to the Iwakuro, the tanks are practically identical, but with a difference in power/weight, armour construction, etc.

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After the 100t model was halted in construction, the Japanese continued with more O-I variants and modifications. Two more Superheavy tanks were produced, the 120t and 130t models. These projects began in 1943 to 1944. Both tanks had 200mm of frontal armour and 150mm on the sides and rear. Both were given the modified Type92 10cm Cannon, that had a recorded range of over 18,200 meters in fire distance, with a fire velocity of 765m/s. It's tested penetration reached 105mm of penetration at 1000 meters. The 130t O-I was a recorded speed of 25-35 km/h, but due to mechanical breakdowns the Japanese couldnt afford to continue the production. The 120t's background is shady. It was recorded as being constructed, however before the part were assembled they were sent to Manchukuo, what happened after is unknown.

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Diagram of the 130t O-I​

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120t O-I​

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After the 15 years war had finally entered its last stages, the Japanese were rendered to near exhaustion from the countless defeats, and due to American bombings the resources reached its limits. This did not stop the Japanese from conducting its last heavy tank attempt. In 1945 the Imperial Japanese Army decided to try and produce a tank to be used as a defense position against approaching Americans. This was Japan's last heavy tank project.. a two engine super heavy tank designed to be larger than the O-I... being 5 meters. The tank was titled the Type2604. The tank was partially built with the Third Year Naval 14cm warship gun. However by the time the turret and gun were formed together, the project was halted and the piece was used as a defense position on one of the Pacific islands.

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Below are some size comparisons that were drawn by Yuri Pasholok recently. While they have some errors, the diagrams are more-less an accurate representation of the Japanese heavy tanks and their sizes.​

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O-I 120t [blue], the T-34 [geen] (U.S.) and KV-5 [red] (Soviet). However the O-I 120t should be a little taller.​

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Second is the O-1 100t {red} and the T-39 {blue} (Soviet). The O-I 100t should be longer here.​

"On the Plains of Hesitation, lies the blackened bones of countless millions who,
at the dawn of victory sat down to rest, and resting died"....(Adlai Stevenson to Harry Truman on discussing the pros and cons of dropping the big one, or so I'm told)

"The farthest they were placed was during the Shanghai incident, where Japanese forces defended themselves against attacking Chinese Nationalists."(Ae Sun)

typical story twisting:

wikipedia: read, and try to find who was the underdog, and who the aggressor...

Naming
In Chinese literature it is known as the January 28 Incident (simplified Chinese: 一·二八事变; traditional Chinese: 一·二八事變; pinyin: Yī Èrbā Shìbiàn), while in Western sources it is often called the Shanghai War of 1932 or the Shanghai Incident. In Japan it is known as the First Shanghai Incident, alluding to the Second Shanghai Incident, which is the Japanese name for the Battle of Shanghai that occurred during the opening stages of the Second Sino-Japanese War in 1937.

Background
After the Mukden Incident, Japan had acquired the vast northeastern region of China and would eventually establish the puppet government of Manchukuo. However, the Japanese military planned to increase Japanese influence further, especially into Shanghai where Japan, along with the various western powers, had extraterritorial concessions.
In order to provide a casus belli to justify further military action in China, the Japanese military instigated seemingly anti-Japanese incidents. On January 18, five Japanese Buddhist monks, members of an ardently nationalist sect, were beaten near Shanghai's Sanyou Factory (simplified Chinese: 三友实业社; traditional Chinese: 三友實業社; pinyin: Sānyǒu Shíyèshè) by agitated Chinese civilians. Two were seriously injured, and one died.[2] Over the next few hours, a group burnt down the factory (sources argue this was orchestrated by Japanese agents,[2] though it might have been carried out by Chinese in response to the Shanghai Municipal Police's aggressive anti-riot tactics in the aftermath of the beating of the monks).
One policeman was killed and several more hurt when they arrived to quell the disorder.[2] This caused an upsurge of anti-Japanese and anti-imperialist protests in the city and its concessions, with Chinese residents of Shanghai marching onto the streets and calling for a boycott of Japanese-made goods.

The battle

Japanese troops burning residential districts.

The situation continued to deteriorate over the next week. By January 27, the Japanese military had already concentrated some thirty ships, forty airplanes and nearly seven thousand troops around the shoreline of Shanghai, in order to put down any resistance in the event that violence broke out. The military's justification was that it had to defend its concession and citizens.
The Japanese also issued an ultimatum to the Shanghai Municipal Council demanding public condemnation and monetary compensation by the Chinese for any Japanese property damaged in the monk incident, and demanding that the Chinese government take active steps to suppress further anti-Japanese protests in the city. During the afternoon of January 28, the Shanghai Municipal Council agreed to these demands.
Throughout this period, the Chinese 19th Route Army (simplified Chinese: 十九路军; traditional Chinese: 十九路軍; pinyin: shíjǐulùjūn) had been massing outside the city, causing consternation to both the civil Chinese administration of Shanghai and the foreign-run Concessions. The 19th Route Army was generally viewed as little more than a warlord force, posing as great a danger to Shanghai as the Japanese military. In the end, Shanghai donated a substantial bribe to the 19th Route Army, hoping that it would leave and not incite a Japanese attack.
However, at midnight on January 28, Japanese carrier aircraft bombed Shanghai in the first major aircraft carrier action in the Far East. Barbara W. Tuchman described this as also being "the first terror bombing of a civilianpopulation of an era that was to become familiar with it",[3] preceding the Condor Legion's bombing of Guernica by some five years. Three thousand Japanese troops attacked various targets, such as the northern train station, around the city and began an invasion of the de facto Japanese settlement in Hongkew and other areas north of Suzhou Creek. In what was a surprising about-face for many, the 19th Route Army, which many had expected to leave after having been paid, stayed to put up a fierce resistance.
Though the opening battles took place in the Hongkew district of the International Settlement, the conflict soon spread outwards to much of Chinese-controlled Shanghai. The majority of the Concessions remained untouched by the conflict and it was often the case that those in the Shanghai International Settlement would watch the war from the banks of Suzhou Creek. They could even visit the battle lines by virtue of their extraterritoriality. On January 30, Chiang Kai-shek decided to temporarily relocate the capital from Nanjing to Luoyang as an emergency measure, since Nanjing's proximity to Shanghai could make it a target.
Because Shanghai was a metropolitan city with many foreign interests invested in it, other countries, such as the United States, the United Kingdom and France attempted to negotiate a ceasefire between Japan and China. However, Japan refused, continuing instead to mobilize troops in the region. On February 12, American, British and French representatives brokered a half-day cease fire for humanitarian relief to civilians caught in the crossfire.
The same day, the Japanese issued another ultimatum, demanding that the Chinese Army retreat twenty kilometers from the border of Shanghai Concessions, a demand promptly refused by the Chinese forces. This only intensified fighting in Hongkew. The Japanese were still not able to take the city by the middle of February. Subsequently, the number of Japanese troops was increased to nearly ninety thousand with the arrival of the 9th Infantry Division and the IJA 24th Mixed Brigade, supported by eighty warships and three hundred airplanes.
On February 14, Chiang Kai-shek sent his 5th Army, including his 87th and 88th divisions, into Shanghai.
On February 20, Japanese bombardments were increased to force the Chinese away from their defensive positions near Miaohang, while commercial and residential districts of the city were set on fire. The Chinese defensive positions deteriorated rapidly without naval and armored support, with the number of defenders dwindling to fewer than fifty thousand. Japanese forces increased to over a hundred thousand troops, backed by both aerial and naval bombardments.
On February 28, after a week of fierce fighting characterized by the stubborn resistance of the Cantonese troops, the Japanese, supported by superior artillery, took the village of Kiangwan (now Jiangwanzhen) north of Shanghai.[4]
On February 29, the Japanese 11th Infantry Division landed near Liuhe behind Chinese lines. The defenders launched a desperate counterattack from 1 March but were unable to dislodge the Japanese. On March 2, the 19th Route Army issued a telegram stating that it was necessary to withdraw from Shanghai due to lack of supplies and manpower. The next day, both the 19th Route Army and the 5th Army retreated from Shanghai, marking the official end of the battle.

more images of fantastic plans that would make a german subject proud (but never realised, and no proof of test models or whatever...any shred of tangible proof being" lost" "disappeared". only handsketches and most of it definitely not original .):http://discaircraft.greyfalcon.us/HAUNEBU.htm

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